The Protective Effects Of Cyanidin-3-O-glucoside On Ultraviolet-Induced Skin Chronic Photodamage In Female Mice

Due to the destruction of the ozone layer,the strength of UV rays reaching the ground is increasing.The over-exposure of human skin to UV rays will lead skin photodamage,including acute damage and chronic damage.Particularly,skin chronic photodamage is closely linked to human health with persistent,difficult diagnosis,and irreversible characteristics.Cyanidin-3-O-glucoside(C3G)is a kind of flavonoid compound widely distributed in fruits and vegetables with numerous bioactivities,including antioxidant activity and anti-inflammatory capacity.It could be considered as the potential component for protecting skin photodamage caused by UV radiation.This study aims to investigate the protective effects and mechanisms of C3 G on skin chronic photodamage by feeding and applying C3 G to mice exposed to UVA+UVB mixed UV.Female mice(4-6 weeks old)were irradiated UV once per two days to damage the dorsal skin.Meanwhile,mice were given supplement by feeding with C3 G forage(1000 mg/kg)or topical applying C3 G cream(5 mg/m L)on the mice dorsal skin for 13 weeks.After the experiment,the mice were photographed,subsequently,the serum and skin tissue were obtained to measure following parameters.(1)The changes in the appearance of the mouse skin were recorded and evaluated.Skin barrier function associated indicators were characterized through VAPOMETER.And the pathological changes of skin tissue were evaluated by hematoxylin-eosin staining.(2)The antioxidant enzymes and lipid peroxidation products in the skin were measured by kits and enzyme linked immunosorbent assay to evaluate the protective effects of C3 G on skin antioxidant system.Skin DNA Damage marker was determined by Immunohistochemistry(IHC),apoptosis was measured by TUNEL fluorescence,the expression of apoptosis-related proteins in skin cells were measured by Western Blot to investigate the protective effects of C3 G on oxidative damage-mediated DNA damage.(3)Real-time quantitative PCR(q PCR),IHC,and WB were applied for analyzing the expression levels of inflammation-related genes and inflammatory cell infiltration in mouse skin to evaluate the protective effect of C3 G on UV-induced inflammation.(4)To study the mechanism of C3 G on the destruction of collagen homeostasis by UV radiation,Masson staining was applied for evaluating the collagen fibers in the dermis of the skin,hydroxyproline kit was applied for collagen quantification,IHC and q PCR were applied for analyzing the expression levels of genes related to collagen synthesis and degradation.The results showed that skin were exhibited a series of phenomena after UV radiation,including darkening,rough with hardening,tarnish,sun scars formation,epidermal hyperplasia,and transdermal water loss.After the intervention of C3 G,above mentioned phenomena were obtained an effective amelioration,and the skin barrier function also has been repaired.C3 G supplements given by oral feeding or C3 G topically apply could significantly improve the skin antioxidative system to reduce the oxidative damage of DNA in comparison with the UV radiation group.In addition,C3 G supplements given by oral feeding or C3 G topically apply can significantly down-regulate the expression levels of inflammation-related genes and reduce the infiltration of inflammatory cells.After the mice dorsal skin exposed to UV radiation,the collagen fibers of the skin appeared disordered and abnormally deposited.C3 G supplements given by oral feeding or C3 G topically apply can improve this abnormal deposition of collagen fibers by regulating the synthesis and degradation of collagen.This study demonstrated that C3 G supplementation could significantly attenuate the skin chronic photodamage,and provide a theoretical basis for anthocyanins in protecting skin chronic photodamage.